Right, when you have fog or freezing fog, of course you have those temps and dew points I mentioned, so perfect icing conditions for real pilots. To check whether you may be going to fly in such conditions, just check your local weather report. Remember all who read this, when the dew point and the ambient temp are the same or close to each other, that is the only time you will have a chance of icing conditions while flying anything. The further away from each other these two temps are, the less likely you will ever encounter icing conditions, and that, luckily, are the temps/conditions you will find most of the time, for most of us flyers.
To see so many people up there on Sledges and skiing etc, must have been a wonderful sight. Reminds me of what the old days used to be like. My uncle used to build us a sledge (UK Speak)/Sled out of wood and we used to go up the mountain by our house in Crosskeys and slide down through the fields. When I was very young, I remember having a pair of wool socks put on my hands because we had no gloves. It was the sort of winter you see in that old classic film, "A Childs Christmas In Wales", with the singing around the piano in the front room, my grandfather and mum were excellent players and singers. Half the street would drop by at some point, during the day, and we would be going out for sledge riding and staying out until it got dark.
There was one winter before I was born where the snow was so deep they had to dig out from the front door to get into the street, my grand parents told me. Ahh the good old days. Thankfully where I live now, we do get snow, in fact have some on the ground now and are expecting more for Christmas Eve throughout the night. I'll search through to find your posted photos, thanks.